Medical and biological engineering

, Volume 14, Issue 5, pp 570–579 | Cite as

Theory of evaluation of the single pneumatic resistor decompression computer

  • R. S. Howard
  • H. Bradner
  • K. Schmitt
Article

Abstract

The development of decompression meters is historically reviewed. The theory of the popular automatic decompression meter marketed by Scubapro is critically discussed, and it is shown that the meter's time constant varies inversely with dive depth. Thus, the meter is a ‘multitissue’ device. The meter's performance is compared with the US Navy's ‘no decompression limits’. It is concluded that use of the meter by recreational divers should be discouraged.

Keywords

Analogue simulation Decompression Diving physiology 

Sommaire

Ce mémoire présente l'historique des compteurs de décompression. Le principe du compteur de décompression automatique universel introduit sur le marché par Scubapro fait l'objet d'un examen critique, et l'on démontre que la constante de temps du compteur varie inversement avec la profondeur de plongée, donc que le compteur est un dispositif à ‘tissus multiples’. La performance du compteur est comparée à l'état ‘sans limitation de décompression’ de la marine américaine. On en conclut qui'l s'agit de décourager l'utilisation de ce compteur par les plongeurs sportifs.

Zusammenfassung

Die Entwicklung von Dekompressionsmessern wird aus historischer Sicht betrachtet. Es folgt eine kritische Beurteilung des beliebten, von Scubaprop vertriebenen automatischen Dekompressionsmessers, und es wird nachgewiesen daß sich die Zeitkonstante des Messers im umgekehrten Verhältnis zur Tauchtiefe ändert, so daß der Messer eine ‘Mehrfachgewebe-Vorrichtung’ darstellt. Die Leistungsfähigkeit des Geräts wird mit den ‘ohne Dekompression Grenzen der US-Marine verglichen. Man gelangt zu dem Schluß, daß der Gebrauch dieses Meßgerätes durch Freizeittaucher abgelehnt werden sollte.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Albano, G. (1960) Etudes sur la decompression chez l'homme. I.er Coll. Int. Med. Sous-Mar., Cannes.Google Scholar
  2. Albano, G. (1970)Principles and observations on the physiology of the scuba diver. ONR Report DR-150.Google Scholar
  3. Alinari, C. (1964) U.S. Patent 3, 121, 333, Indicating instrument for divers, Feb. 18, 1964.Google Scholar
  4. Anderson, D. (1967) The automatic decompression meter.Skin Diver Mag., November, 53.Google Scholar
  5. Anonymous (1962) New safety aid.Skin Diver Mag., May, 22.Google Scholar
  6. Borom, M. P., Johnson, L. A. (1973) A decompression meter for scuba diving utilizing semipermeable membranes. General Electric Report 73CRD129.Google Scholar
  7. Borom, M. P. andJohnson, L. A. (1974) Decompression meter for scuba diving utilizing semipermeable membranes.Aerospace Med.,45, 135–142.Google Scholar
  8. Boycott, A. E., Damant, G. C. C. andHaldane, J. S. (1908) The prevention of compressed air illness.J. Hyg. Camb.,8, 343–443.Google Scholar
  9. Bradner, H. andMackay, R. S. (1963) Biophysical limitations on deep diving; some limiting performance expectations.Bull. Math. Biophys.,25, 251–272.Google Scholar
  10. Carman, P. C. (1956) Flow of gases through porous media, Butterworths, London.MATHGoogle Scholar
  11. Collins, R. E. (1961) Flow of fluids through porous materials, Reinhold, New York.Google Scholar
  12. Cross, E. R. (1965) How reliable is a meter?Skin Diver Mag., November, 26.Google Scholar
  13. Cross, E. R. (1968) How good are automatic decompression meters?Skin Diver Mag., May, 48.Google Scholar
  14. Des Granges, M (1957) Repetitive diving decompression tables. US Navy EDU Research Report, 6-57.Google Scholar
  15. Doak, W. andMcKenney, J. (1970) Getting to know your decom meter.Skin Diver Mag., April, 22–28.Google Scholar
  16. Edel, P. O. (1971) Computer controlled decompression procedures in hyperbaric-hypobaric profiles. J & J Marine Diving Co., Inc.Google Scholar
  17. Egstrom, G. H. (1970) Discussion. InHuman performance and scuba diving, p. 30. The Athletic Institute, Chicago.Google Scholar
  18. Frederickson, P. (1956) The analysis and testing of decomputer (Mark I). Foxboro Company Research Report MR-138.Google Scholar
  19. G.E.R.S. (1962) ‘Spiro-sub’ decompression meter. Groupe D'Etudes et de Recherches Sous-Marines Report G.E.R.S. 1/62.Google Scholar
  20. Groves, G. andMunk, W. (1953) A decompression gauge for divers. Scripps Institution of Oceanography Reference 53–64.Google Scholar
  21. Hawkins, T. L. (1974) Underwater decompression computer.Faceplate, Spring, 24.Google Scholar
  22. Hennessy, T. R. (1973) The equivalent bulk-diffusion model of the pneumatic decompression computer.Med. & Biol. Eng.,11, 135–137.CrossRefGoogle Scholar
  23. Hills, B. A. (1966)A thermodynamic and kinetic approach to decompression sickness. S. Australian Pub. Libr., Adelaide.Google Scholar
  24. Hills, B. A. (1967a) A pneumatic analogue for predicting the occurrence of decompression sickness.Med. & Biol. Eng.,5, 421–432.Google Scholar
  25. Hills, B. A. (1967b) A thermal analogue for the optimal decompression of divers: theory.Phys. Med. & Biol.,12, 437–444.CrossRefGoogle Scholar
  26. Hills, B. A. (1967c) A thermal analogue for the optimal decompression of divers: construction and use.Phys. Med. & Biol.,12, 445–454.CrossRefGoogle Scholar
  27. Hills, B. A. (1968) Analogues for indicating the optimal decompression of divers.Aust. J. Instrum. & Control,24, 3–9.Google Scholar
  28. Hills, B. A. (1970) Vital issues in computing decompression schedules from fundamentals II. diffusion versus blood perfusion in controlling blood: tissue exchange.Int. J. Biometeor.,14, 323–342.CrossRefGoogle Scholar
  29. Hills, B. A. (1975a) Decompression meter based upon zero supersaturation of tissue. InSixth symposium on underwater physiology, in prep.Google Scholar
  30. Hills, B. A. (1975b) personal communication.Google Scholar
  31. Howard, R. andSchmitt, K. (1975) The decompression meters—another look.The Undersea Journal,8, (3), 9–13.Google Scholar
  32. Howard, R. Schmitt, K., andHuisveld, P. (1974) Preliminary observations on the Farallon decomputer. Unpublished data.Google Scholar
  33. Kidd, D. J. andStubbs, R. A. (1969) The use of the pneumatic analogue computer for divers. InThe physiology and medicine of diving, Eds. Bennett, P. B. and Elliott, D. H., pp. 386–413. Bailliere, Tindall & Cassell, London.Google Scholar
  34. Kidd, D. J. Stubbs, R. A. andWeaver, R. S. (1971) Comparative approaches to prophylactic decompression. InProceedings of the fourth symposium on underwater physiology, Ed. Lambertsen, C. N. Academic Press.Google Scholar
  35. Kuehn, L. A., andNishi, R. Y. (1975) The use of decompression computers in diving.Proceedings of the symposium on chemistry and physics of aqueous gas solutions, Electrochemical Society, pp. 486–497.Google Scholar
  36. Millikan, R. (1923) Coefficients of slip in gases and the law of reflection of molecules from the surfaces of solids and liquids.Phys. Rev.,21, 217–238.CrossRefGoogle Scholar
  37. Mount, T. (1971) The decom meter vs. US Navy tables.Skin Diver Mag., November, 32–35.Google Scholar
  38. Nishi, R. (1973) Calibration procedures for pneumatic analogue decompression computers. Defence and Civil Institute of Environmental Medicine, Report 918.Google Scholar
  39. Nishi, R. Y. andKuehn, L. A. (1972) Pneumatic and electronic decompression computers. InFifth symposium on underwater physiology, in preparation.Google Scholar
  40. Quick, D. (1974) Evaluation of the automatic decompression meter. Royal Australian Navy School of Underwater Medicine project 2/74.Google Scholar
  41. Seiple, R. L., Jennings, K. E. andLosee, J. R. (1973) Advanced technology for a diver depth gauge and decompression computer. NUC TN 949.Google Scholar
  42. Spencer, M. P. andJohanson, D. C. (1974) Investigation of new principles for human decompression schedules using the doppler ultrasonic blood bubble detector, pp. 59–60. Technical report, ONR contract N00014-73-C-0094.Google Scholar
  43. Stewart, J. R. (1970) Discussion. InHuman performance and scuba diving. p. 31. The Athletic Institute, Chicago.Google Scholar
  44. Stubbs, R. A. andKidd, D. J. (1965a) A pneumatic analogue decompression computer. Canadian Forces Medical Service, Institute of Aviation Medicine, Report 65-RD-1.Google Scholar
  45. Stubbs, R. A. andKidd, D. J. (1965b) Control of decompression by analogue computer. Canadian Forces Medical Service, Institute of Aviation Medicine, Report 65-RD-8.Google Scholar
  46. Stubbs, R. A. andKidd, D. J. (1967) Computer analogues for decompression. InProceedings of the third symposium on underwater physiology, Ed. Lambertsen, C. N. Williams & Wilkins, Baltimore.Google Scholar
  47. Todd, G. P. (1969) Decompression patterns developed by an interdependent electric analog. USN Sub. Med. Cnt. report 580.Google Scholar
  48. Weaver, R. S. (1967) Pneumatic analogue computer control of decompression. InDecompression of compressed air workers in civil engineering, Ed. McCallum, R.I., Oriel, London.Google Scholar
  49. Weaver, R. S. Kuehn, L. A. andStubbs, R. A. (1968) Decompression calculations: analogue and digital methods. DRET Report 703.Google Scholar
  50. Weaver, R. S. andStubbs, R. A. (1968) The transient response of an m-loop filter system with special application to the decompression problem in man: non-linear model. DRET Research Paper 674.Google Scholar
  51. Wittenborn, A. F. (1963) An analytical development of a decompression computer.In Proceedings—second symposium on underwater physiology, Nat. Acad. Sci.—Nat. Res. Council Publication 1181.Google Scholar
  52. Wolfinger, P. (1974) Meter final.Amphibian July/August, 9–21.Google Scholar
  53. Workman, R. D. (1963) Evaluation of a decompression computer developed for divers. USN EDU evaluation report 1-63.Google Scholar
  54. Workman, R. D. (1965) Calculation of decompression schedules for nitrogen-oxygen and helium-oxygen dives. USN EDU research report 6-65.Google Scholar

Copyright information

© International Federation for Medical & Biological Engineering 1976

Authors and Affiliations

  • R. S. Howard
    • 1
  • H. Bradner
    • 1
  • K. Schmitt
    • 1
  1. 1.Scripps Institution of OceanographyLa JollaUSA

Personalised recommendations